Wind turbines of the horizontal-axis type are commonly used for the generation of electric power. Such wind turbines have an impeller that is commonly held high above the ground and exposed to the wind. The impeller is typically connected to a shaft extending into a nacelle, with the shaft being connected to a mechanism that will transmit wind forces to a generator.
In order to maximize the generation of power, it is desired to align the impeller at a desired orientation relative to the wind, e.g., having a plane of the impeller perpendicular to the wind, or the rotational axis of the impeller parallel to the wind. For this purpose, a wind vane or wind indicator is provided on top of the nacelle of the wind turbine, to provide an indication of the direction of the wind. The indication of the wind direction may then be used to adjust an orientation of the impeller, by rotating the nacelle supporting the impeller about its vertical axis, i.e., about the tower supporting the nacelle.
One of the issues pertaining to wind turbines of the horizontal-axis type is the calibration of the wind indicator or wind vane relative to the orientation of the impeller. Indeed, it is desired to align the impeller with a direction of the wind to maximize the amount of force collected from the wind. However, if the calibration of the wine indicator/vane relative to the wind turbine is imprecise, the orientation of the impeller may also lack precision and hence not be optimal for maximizing the amount of force collected from the wind.